Psychometric properties and measurement invariance of the 7-item General Anxiety Disorder scale (GAD-7) in an Italian coronary heart disease population

Background: Generalized Anxiety Disorder is predominant in coronary heart disease (CHD) patients. 7-item Generalized Anxiety Disorder (GAD-7) scale psychometric properties have never been tested in CHD pop-ulations. This study aims to verify the GAD-7 psychometric properties and measurement invariance in an Italian CHD sample.Method: A baseline data secondary analysis from HEARTS-IN-DYADS study. Several healthcare facilities enrolled an adult inpatient sample. Anxiety and depression data were collected using GAD-7 and Patient Health Ques-tionnaire 9 (PHQ-9). Factorial validity was assessed with confirmatory factor analysis; construct validity was tested by correlating GAD-7 scores with PHQ-9 scores and other sociodemographic characteristics; internal consistency reliability was assessed using Cronbach's alpha and the composite reliability index, while confir-matory multigroup factor analysis was employed to investigate measurement invariance across gender and age (65 vs. 65).Results: We enrolled 398 patients (mean age 64.7 years; 78.9 % male; 66.8 % married). Factor structure was confirmed as unidimensional. Construct validity was confirmed with significant associations between GAD-7 and PHQ-9 scores, female gender, having a caregiver, and being employed. Cronbach's alpha and composite reli-ability index were 0.89 and 0.90, respectively. Measurement invariance across gender and age was confirmed at the scalar level.Limitations: A convenience sample in one European country, a small female sample, validity testing against a single criterion.Conclusion: Study results demonstrate adequate validity and reliability of the GAD-7 in an Italian CHD sample. It showed satisfactory invariance properties; GAD-7 is suitable for measuring anxiety in CHD while making sig-nificant comparisons of scores among stratified gender and age groups.